(i) Field of the Invention
This invention relates to an endless transmission belt suitable for use in V-belt type stepless or continuous transmissions.
(ii) Description of the Prior Art
In our prior application, Japanese laid-Open Patent Application No. 58-21043 corresponding to U.S. Pat. No. 4,545,779) proposes an endless drive belt for transmitting torque between a couple of pulleys of the type having a pair of conical contact surfaces opposingly disposed in coaxial relation with each other. The endless belt comprises a multitude of chained trapezoidal metal blocks each having inclined contact surfaces formed on part or entire areas of lateral side surfaces for engagement with the contact surfaces of the pulleys. More particularly, the endless drive belt of our prior application employs metal blocks each comprising a plate of trapezoidal shape in front view, having the inclined contact surfaces formed on part or entire areas of its lateral side surfaces and having, bored through its thickness, one or two apertures with predetermined dimensions in widthwise direction or one or two notches opened on the outer pheripheral edges thereof, and an endless link chain comprising a multitude of link units of uniform lengths connected with each other at the opposite ends thereof. The link chain has a width which can be fitted in the above-mentioned aperture or notch, the links being longitudinally inserted in the apertures or notches of the metal blocks crosswise. The metal blocks are each connected to the link chain by at least one shaft and are successively mounted along the length of the link chain, transferring the transmitted force from a preceding metal block to a succeeding metal block through the link chain. In this case, the blocks are retained in position by pins (connecting means) in order not to subject the links to unnecessary forces other than the transmitting torque.
However, as each metal block is located between adjacent pins in the endless transmission belt of the above-described arrangement, there is a possibility of impairing durability of the blocks which have to bear relatively large loads.